Order 1,2,10,11 instead 1,10,11,2

Question

I have files in my folder with names like these:

"C:\\Users\\John\\Documents\\333\\12.html"

How to sort them so that 2.html will come before 10.html?

Windows Explorer? Norton Commander? `DirectoryInfo.GetFiles()`? — CodeCaster, Apr 19 '12 at 12:31
possible duplicate of [Natural Sort Order in C#](http://stackoverflow.com/questions/248603/natural-sort-order-in-c-sharp) — CodeCaster, Apr 19 '12 at 12:33
Get the files in a list by using DirectoryInfo.GetFiles() and then sort them on the basis of their name. Read more here: http://msdn.microsoft.com/en-us/library/system.io.directoryinfo.getfiles.aspx — Prashant, Apr 19 '12 at 12:36

score 4 · Accepted Answer · answered Apr 19 '12 at 12:34

4

Parse the strings as numbers when you sort the files.

Example:

string[] files = {
  "2.html",
  "10.html",
  "1.html"
};

files =
  files.OrderBy(s => Int32.Parse(s.Substring(0, s.IndexOf('.'))))
  .ToArray();

answered Apr 19 '12 at 12:34

Guffa

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And then it will fail on "Part 1.html", "a.html" and "b.html". Your solution will only work in the specific case of file names looking like `.`. – penartur Apr 19 '12 at 12:39
@penartur : conform the specs. Read the question. – H H Apr 19 '12 at 12:40
The question says "file names are **like** `3.html`", not "file names are exactly `.`". In the context of question, `part 3.html` is like `3.html`. – penartur Apr 20 '12 at 08:05
@penartur: The example shows what kind of strings it works with. Whatever anyone may think about what the question means, the answer in itself defines what question it is answering. – Guffa Apr 20 '12 at 08:39

H H · Answer 2 · 2012-04-19T12:41:25.867

2

    Directory
      .GetFiles()
      .OrderBy(f => int.Parse(Path.GetFileNameWithoutExtension(f)) )

edited Apr 19 '12 at 12:41

answered Apr 19 '12 at 12:35

H H

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Dor Cohen · Answer 3 · 2012-04-19T12:40:52.060

1

Look at this post -

http://www.codeproject.com/Articles/11016/Numeric-String-Sort-in-C

string[] files = System.IO.Directory.GetFiles();

NumericComparer ns = new NumericComparer();
Array.Sort(files, ns);

// files will now sorted in the numeric order
// we can do the same for directories

string[] dirs = System.IO.Directory.GetDirectories();
ns = new NumericComparer(); // new object
Array.Sort(dirs, ns);

public class NumericComparer : IComparer
    {
        public NumericComparer()
        {}

        public int Compare(object x, object y)
        {
            if((x is string) && (y is string))
            {
                return StringLogicalComparer.Compare((string)x, (string)y);
            }
            return -1;
        }
    }//EOC

edited Apr 19 '12 at 12:40

answered Apr 19 '12 at 12:32

Dor Cohen

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In what anmespace is NumericComparer ? – user1322207 Apr 19 '12 at 12:37
@user1322207 Look at the link there is a source example to download, I also edit my answer – Dor Cohen Apr 19 '12 at 12:41

Order 1,2,10,11 instead 1,10,11,2

3 Answers3